Hello,
The latest download of Calibre includes experimental conversion to KF8.:

----------------------------------------------------------------------------
'calibre can now generate Amazon's new KF8 format MOBI files. To turn on this feature, go to Preferences->Tweaks and click Plugin Tweaks. In the box add: test_mobi_output_type = 'both' calibre will now produce MOBI files that have both the old MOBI format and the new KF8 format in them. To learn more about KF8, see: http://www.amazon.com/gp/feature.html?docId=1000729511 Note that calibre support for KF8 is still experimental and there will likely be bugs.'
----------------------------------------------------------------

I've tried to follow the instructions - but when I do a conversion all I get is one Mobi file - no KF8.

From what I understand of this feature nothing is wrong. The single MOBI file contains both KF8 and MOBI formats inside it, just like the files from Amazon do. Calibre will not create two separate files.

I tried this myself and found it to work well. Indeed, when viewing the post conversion mobi file with Calibre's own viewer, I noticed that the book's title had [KF8] next to it in the title bar. A nice touch.

Then you should open a bug report and attach the original azw3 and describe the problem.

I can't, the original is DRM protect. I have purchased it from Amazon. I dedrm it and the Kindle non recognize the mobi. I unpacked the mobi, import the epub in Calibre and then in the Kindle and now it recognizes the mobi but without the original font.

Is there a trick to getting a KF8 file onto my updated Kindle Keyboard? I converted a file from straight .mobi to the "new" format and transferred it to my Kindle. I got an error stating the file could not be opened and if purchased from Amazon, download it again.

I just want to be perfectly clear here: Calibre's KF8 conversions aren't functional on e-ink devices, only in the calibre viewer? And conversions that contain both MOBI and KF8 will only render MOBI on those devices? But AZW3 has all the same HTML capabilities as KF8?

EDIT:
When I try to sync an AZW3 to my kindle, I get a message from calibre saying that there aren't any recognized formats for my device and that i should convert the file. I'm getting more and more confused.

EDIT2:
If i convert to MOBI, with the old & new formats contained within it, it renders KF8 almost perfectly (minus the .ncx), rendering HTML that the old MOBI couldn't render (such as hanging indents). Color me even more confused.